HDPE pipe saves the day at air force base

Left: Crews at Vandenberg Air Force Base used 3600 feet of 60-inch HDPE pipe. The entire project used 5000 feet of HDPE pipe to divert stormwater from the landfill to a creek via collection pipes ranging from 24- to 48-inch diameters. Right: Project supervisors estimated that 75% of the pipe was laid at depths of more than 20 feet. Using HDPE pipe eliminated the need for a crane in a right-of-way that was only about 120 feet.

The landfill at California's Vandenberg Air Force Base (AFB) performs its intended function well but—according to the U.S. Environmental Protection Agency— its performance as a ponding basin for stormwater runoff was less impressive.

The landfill receives a fair amount of rainwater runoff, and new EPA regulations now restrict overflow from collecting in landfill basins. Engineers at the base needed an immediate solution at an affordable price.

“The cost and the timeline for the project were directly related,” said project supervisor Ed Kleman of ACE Engineering in La Verne, Calif, the contracting firm for Vandenberg AFB. “Once we hit a certain amount, the project had to go to bid, which could have cost us up to three years. This had to be done now.”

The use of corrugated high-density polyethylene (HDPE) pipe enabled engineers to bring the project—which started in August 2003 and ended in early 2004— in under the target cost.

The project called for stormwater to be diverted from the landfill to a creek via collection pipes that ranged in diameter from 24 to 48 inches. That water then would be routed through a 60-inch pipe and into a riprap filter—allowing for settlement of sediment and some pollutants before discharging into the stream.

“Quantity of stormwater is no longer the only consideration for drainage projects,” said Rich Gottwald, president of the Washington, D.C.-based Plastics Pipe Institute (PPI). “Managing the quality of the runoff is now a way of life for civil engineers and community leaders.”

PPI applications engineer Jeffrey Hiott added that even in a climate like southern California, which has a modest amount of rainfall, it's all about where that stormwater is directed, not how much of it there is. “Besides carrying water to an alternative destination, it's vital that the storm-water stays in the pipe until it gets where it's supposed to go,” said Hiott.

The job at the base used 5000 feet of HOPE pipe, 3600 feet of which was 60 inches in diameter. Kleman used 13-foot sections of HDPE pipe at Vandenberg AFB that weighed 700 to 800 pounds each. Moreover, Kleman estimated that 75% of the pipe was laid at depths of more than 20 feet. Using HDPE eliminated the need for a crane, which was a tremendous benefit considering the right-of-way was only about 120 feet wide.

“It really cut down on the people we had to have in the trench,” said Kleman. “That means labor costs are down and safety measures are up. Not to mention, if the pipe is just a little offline, with HDPE you can literally kick it into place.” Kleman added that much of the time savings occurred when contractors were forced to cut a piece of pipe in the field to fit a particular section.

The base is situated about 150 miles northwest of Los Angeles and supports a population of about 16,500, including the military, their family members, contractors, and civilian employees. Vandenberg AFB is the only military base in the United States from which unmanned government and commercial satellites are launched into polar orbit. It is also the only site from which intercontinental ballistic missiles are test fired into the Pacific Ocean where they splash down at the Kwajalein Atoll in the Marshall Islands.